Farquhar, who suffered a brain hemorrhage earlier this year during a game, was outrighted to Triple-A Charlotte in a roster move by the White Sox. That decision means he will become a minor league free agent after the World Series ends, making him free to sign with any team.
Outfielder Ryan LaMarre and right-handed pitcher Rob Scahill were also outrighted to Charlotte.
"Today's transactions provide us with roster flexibility as we head into this offseason," White Sox G.M. Rick Hahn said. "We do plan to continue to stay in touch with these players and their representatives over the coming months to see if it makes sense for any of them to remain with our organization as we head into the 2019 season."
The White Sox had also placed catcher Kevan Smith on waivers, but he was claimed by the Los Angeles Angels on Friday.